A61F2/446—Joints for the spine, e.g. vertebrae, spinal discs for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones

A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents

A61F2/02—Prostheses implantable into the body

A61F2/30—Joints

A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof

A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for

A61F2002/30331—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit

A61F2002/30332—Conically- or frustoconically-shaped protrusion and recess

A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents

A61F2/02—Prostheses implantable into the body

A61F2/30—Joints

A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof

A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for

A61F2002/30331—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit

A61F2002/30362—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit with possibility of relative movement between the protrusion and the recess

A61F2002/30364—Rotation about the common longitudinal axis

A61F2002/30367—Rotation about the common longitudinal axis with additional means for preventing said rotation

A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents

A61F2/02—Prostheses implantable into the body

A61F2/30—Joints

A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof

A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for

A61F2002/30331—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit

A61F2002/30362—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit with possibility of relative movement between the protrusion and the recess

A61F2002/3037—Translation along the common longitudinal axis, e.g. piston

A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents

A61F2/02—Prostheses implantable into the body

A61F2/30—Joints

A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof

A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for

A61F2002/30383—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove

A61F2002/3039—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove with possibility of relative movement of the rib within the groove

A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents

A61F2/02—Prostheses implantable into the body

A61F2/30—Joints

A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof

A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for

A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents

A61F2/02—Prostheses implantable into the body

A61F2/30—Joints

A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof

A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for

A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents

A61F2/02—Prostheses implantable into the body

A61F2/30—Joints

A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof

A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for

A61F2002/30507—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements locked by an additional locking mechanism using a threaded locking member, e.g. a locking screw or a set screw

A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents

A61F2/02—Prostheses implantable into the body

A61F2/30—Joints

A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof

A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for

A61F2002/30507—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements locked by an additional locking mechanism using a threaded locking member, e.g. a locking screw or a set screw

A61F2002/3051—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements locked by an additional locking mechanism using a threaded locking member, e.g. a locking screw or a set screw using a locking bolt or a set bolt

A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents

A61F2/02—Prostheses implantable into the body

A61F2/30—Joints

A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof

A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for

A61F2002/30535—Special structural features of bone or joint prostheses not otherwise provided for

A61F2002/30537—Special structural features of bone or joint prostheses not otherwise provided for adjustable

A61F2002/30538—Special structural features of bone or joint prostheses not otherwise provided for adjustable for adjusting angular orientation

A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents

A61F2/02—Prostheses implantable into the body

A61F2/30—Joints

A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof

A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for

A61F2002/30535—Special structural features of bone or joint prostheses not otherwise provided for

A61F2002/30579—Special structural features of bone or joint prostheses not otherwise provided for with mechanically expandable devices, e.g. fixation devices

A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents

A61F2/02—Prostheses implantable into the body

A61F2/30—Joints

A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof

A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for

A61F2002/30535—Special structural features of bone or joint prostheses not otherwise provided for

A61F2002/30594—Special structural features of bone or joint prostheses not otherwise provided for slotted

A61F2002/30596—Special structural features of bone or joint prostheses not otherwise provided for slotted slots ending in apertures, e.g. for avoiding stress concentration at the ends of the slots

A61F2220/0033—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit

A61F2250/00—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof

A61F2250/0004—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof adjustable

A61F2250/0006—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof adjustable for adjusting angular orientation

Abstract

The invention describes a fusion dowel (1) for vertebrae which is used to fuse two adjacent vertebrae of the human spine. Essentially, it comprises a sleeve (2) which is slit lengthwise over essentially two thirds of its length by at least two slots (3) and is thus subdivided into at least two segments which can be spread apart. The sleeve (2) is penetrated by a screw (5) inserted in the sleeve (2) on the proximal front face thereof which is closed except for a bore (6) for the screw (5). A nut (7) having a circular cross-section and an outer surface (8) that widens conically toward the open sleeve end starting from a cylindrical part (7') is placed in the distal end of the sleeve (2). The diameter of the cylindrical section (7') roughly corresponds to the internal diameter of the sleeve (2). The screw (5) can be connected to the nut (7) by screwing. On continuous screwing movement the region of the conically widening outer surface (8) of the nut (7) reaches the front opening of the sleeve (2) and ensures spreading of the wall segments of the sleeve (2) from this point onwards. <IMAGE>

Ein Wirbelsäulenimplantat ist bekannt geworden aus der EP-0 260 044 A1. A spinal implant has become known from EP-0260044 A1.Gemäß einer Ausführungsform ist dort vorgesehen, einen im wesentlichen zylindrischen Körper zweigeteilt aus zwei Halbschalen zu bilden. According to one embodiment there is provided to form a substantially cylindrical body in two parts from two half shells.In deren Inneren ist eine Gewindespindel mit gegenläufigen Gewinden gelagert, auf der zwei Nocken aufgeschraubt sind. Inside which a threaded spindle is mounted with opposite threads, are screwed onto the two cams.Die beiden Nocken sind im nicht-verspannten Zustand des Implantates untergebracht in entsprechend ausgebildeten Taschen in den beiden Zylinderhälften. The two cams are located in the non-tightened state of the implant in accordance with pockets formed in the two cylinder halves.Auf eine Drehung der Gewindespindel zum Verspannen des Implantates in der Wirbelsäule werden diese Nocken aus den besagten Taschen herausgedrängt, so daß die beiden Hälften des zylindrischen Körpers auseinandergespreizt werden. Upon rotation of the threaded spindle for clamping of the implant in the spine, these cams are pushed out of said pockets, so that the two halves of the cylindrical body are spread apart.Es findet demnach eine Parallelverschiebung der Wirbelkörper statt, an denen die beiden Zylinderhälften anliegen. There occurs accordingly a parallel shift of the vertebral body against which the two cylinder halves.

Als problematisch jedoch erweist es sich, daß im Falle der Anbringung einer Bohrung bzw. eines Kanals in einem Wirbelkörper das noch nicht extrahierte Implantat zwar dort hinein gesetzt werden kann, wenn jedoch die Gewindespindel gedreht wird, so daß sich die beiden Zylinderhälften parallel voneinander entfernen, so findet das Implantat lediglich durch einen Preßfit Halt in der Wirbelsäule. A problem, however, it turns out that in the case of mounting a bore or a channel in a vertebra that were not extracted implant can indeed be placed therein, however, when the threaded spindle is rotated, so that the two cylinder halves remove parallel from one another, so the implant is only by a press fit grip in the spine.Am Eingang des Kanals bzw. der eingebrachten Bohrung findet sich bei dem Implantat derselbe Querschnitt wie am Ende des- bzw. derselben, nämlich ein ovaler Querschnitt. At the entrance of the channel or bore introduced, the same cross-section takes place as at the end DES or the same, namely an oval cross-section at the implant.Auf Grund von Belastungen der Wirbelsäule im täglichen Leben kann es nicht ausgeschlossen werden, daß der Preßfit des Implantates gelockert wird und dem Patienten die Gefahr eines Herausrutschens des Implantates aus der Bohrung bzw. aus dem Kanal erwächst. Due to negative effects on the spine in daily life, it can not be excluded that the press fit of the implant is loosened and the patient grows the danger of slipping out of the implant out of the hole and out of the channel.Dies ist nicht akzeptabel. This is not acceptable.

Gemäß einem späteren Vorschlag gemäß der WO 92/14423, in der auch das vorerwähnte Implantat Erwähnung findet, wird dem Herausrutschen aus dem Kanal in den Wirbelkörpern versucht entgegenzuwirken, indem das Implantat nach Einsetzen in den Kanal in seiner Mitte in seinem Querschnitt vergrößert wird. According to a later proposal according to the WO 92/14423, which also includes the aforementioned implant is mentioned, the slipping out of the channel in the vertebral bodies is attempted to counteract by the implant is increased by insertion into the channel at its center in its cross section.Am Anfang und am Ende des Kanals bzw. der Bohrung finden sich die kleinsten Querschnitte, während der Querschnitt des Implantates nach der Implantation und dem Spannen in der Mitte am größten ist. At the beginning and at the end of the channel or bore to find the smallest cross-sections, while the cross section of the implant after implantation, and the tension in the middle is the largest.Es trifft zu, daß dem Herausrutschen hierdurch wirksam entgegengewirkt wird. It is true that the slipping is thereby effectively counteracted.Als nachteilig wird allerdings angesehen, daß die größte Erweiterung bzw. größte Spreizung des Implantates nicht am sozusagen eigentlichen Ort des Geschehens vorgenommen wird, sondern weit dahinter gelegen. A disadvantage is, however, considered that the greatest expansion and largest spread of the implant is not made on it were actual site of the incident, but located far behind it.Der Ort nämlich, wo ein Implantat seine therapeutische Wirkung entfalten sollte, ist der Übergangsbereich von knöchernen Material eines Wirbelkörpers zur Bandscheibe, welche bei der indizierten Operation und Einsatz eines solchen Implantates beschädigt ist. The place namely where an implant should exert its therapeutic effect is the transition area of ​​bony material of a vertebra to the intervertebral disc, which is damaged in the indexed operation and use of such an implant.Im Grenzbereich zwischen knöchernem Material und der beschädigten Wirbelsäule ist dafür Sorge zu tragen, daß die Spreizung in diesem Bereich am größten ist. In the border area between the bony material and the damaged spine, care must be taken that the spread is in this area is the largest.Dies vermag keines der bekannten Implantate zu leisten. This can achieve none of the known implants.

Vor diesem Hintergrund ist es die Aufgabe der vorliegenden Erfindung, ein Implantat zur knöchernen Fixation zweier benachbarter Wirbelkörper der menschlichen Wirbelsäule anzugeben, welches diese Wirbelkörper dauerhaft miteinander verbindet und gleichzeitig für die maximale Spreizung der benachbarten Wirbelkörper im Bereich der Grenzfläche zwischen knöchernen Material und dem Material der Bandscheibe sorgt. Against this background it is the object of the present invention to provide an implant for bone fixation of two adjacent vertebral bodies of the human spine which connects these vertebral bodies permanently bonded together and at the same time for the maximum spread of the adjacent vertebral bodies in the region of the interface between the bony material and the material of the disc provides.

Ausgehend von dem Implantat gemäß der erwähnten WO 92/14423 wird diese Aufgabe durch das Implantat mit den kennzeichnenden Merkmalen des Anspruchs 1 gelöst. Starting from the implant according to the mentioned WO 92/14423, this object is achieved by the implant having the characterizing features of claim 1.Weitere vorteilhafte Ausgestaltungen ergeben sich aus den Unteransprüchen. Further advantageous embodiments result from the dependent claims.Demnach wird vorgeschlagen, das Implantat als eine Art Dübel auszubilden. Accordingly, it is proposed that the implant as a kind of dowel.Wie das Implantat gemäß der vorerwähnten Druckschrift besteht dieses aus einer Hülse und einer die Hülse durchsetzenden Schraube, die an der bis auf eine Durchbohrung für die Schraube geschlossenen proximalen Stirnseite der Hülse in diese eingesetzt ist. As the implant according to the above-mentioned publication this consists of a sleeve and the sleeve passing through screw, which is inserted in the bore to a closed for the screw proximal end face of the sleeve in this.Erfindungsgemäß ist nun vorgesehen, daß wenigstens zwei in der Hülse von ihrem distalen Ende zum proximalen Ende über im wesentlichen 2/3 ihrer Länge verlaufenden Schlitze sowie eine mit der Schraube verschraubbare Mutter vorgesehen sind, die von der distalen Seite in die Hülse greift, wobei die Mutter einen kreisförmigen Querschnitt und ausgehend von einem zylindrischen Teil eine sich zum offenen Hülsenende konisch erweiternde Mantelfläche aufweist und der Durchmesser des zylindrischen Abschnittes in etwa dem Innendurchmesser der Hülse entspricht. According to the invention it is now provided that at least two are provided in the sleeve from its distal end to the proximal end over essentially 2/3 of its length extending slots and a screwed with the screw nut, which engages from the distal side in the sleeve, the mother corresponds to a circular cross-section and has a starting towards said open end of the sleeve flared lateral surface of a cylindrical part and the diameter of the cylindrical portion approximately to the inner diameter of the sleeve.Das bewirkt, daß der zylindrische Abschnitt in der Hülse zunächst geführt werden kann. This causes the cylindrical section can be guided in the sleeve first.

Wie einsichtig ist, wird bei weiterem Anziehen der Schraube die speziell ausgebildete Mutter noch weiter in die Hülse hinein gezogen. As is appreciated, as will be further drawn upon further tightening of the screw the nut specially trained into the sleeve.Ist die Mutter so weit in die Hülse hineingezogen, daß nun nachfolgend die sich konisch aufweitende Mantelfläche an der distalen Stirnseite der Hülse ansteht, und wird die Schraube noch weiter gedreht, so wird die Hülse in diese hineingezogen unter Aufweitung der Wandungssegmente der Hülse. If the mother so far into the sleeve that now below is present, the conically widening circumferential surface on the distal end face of the sleeve, and the screw is rotated still further, the sleeve is in this drawn under widening of the wall segments of the sleeve.Dadurch kommt der bekannte Sperreffekt eines Dübels zustande. Thus, the known barrier effect of a dowel comes about.

Die Handhabung des erfindungsgemäßen Implantats wird in situ noch dadurch deutlich vereinfacht, daß gemäß einer vorteilhaften Ausführungsform einer der Längsschlitze in der Hülse im distalen Bereich als Führungsnut ausgebildet ist, und zwar für einen an der Mutter angebrachten, als Verdrehsicherung wirkender Bolzen. The handling of the implant according to the invention will thus significantly facilitated in situ, that is designed as a guide groove according to an advantageous embodiment, one of the longitudinal slots in the sleeve in the distal region, namely mounted on the nut for one, acting as anti-rotation pin.Hierdurch wird die Mutter vor einem Mitdrehen an Stelle einer Aufweitung der Wandungssegmente gehindert. In this way, the nut is prevented from rotating in front of a place of a widening of the wall segments.

Die Erfindung wird an Hand eines Ausführungsbeispiels gemäß der Zeichnungsfiguren näher erläutert. The invention will be explained in more detail with reference to an embodiment shown in the drawing figures.Hierbei zeigt Here shows